Capping off 15mm copper pipe, but not externally. Possible?

[Dazz71]

Hi.

So, it is basically the title.

Long version:
I am renovating our new place in the highlands, but I am doing it in 2 halves. One side gets done, then the other.
One of the things that needs to be done is take out the old rads and cap off the original 15mm pipes.

The issue is we need to keep some rads working A ND that the new place has concrete floors.
I would like to cut the the pipe flush with the floor level then cap it off internally. Is this possible?

If not what is my next avenue of attack to keep the capped off pipe as low as possible?

Cheers

 

[oldbuffer]

1. Assuming the pipes are copper, there is no normal fitting to block them internally. Same is true for plastic pipes.
2. The smallest caps are solder feed.
3. My approach with readily available fittings would be:
3.1 Cut the pipe level with the concrete. Multi-tool or similar
3.2 Drill out around the pipe stub (assuming vertical) with a core drill - say 25 mm, taking care not to damage the pipe.
3.3 Again with care, scrape any concrete off the pipe and clean up the top.
3.4 Cut a further 4 or 5 mm off the top of the pipe.
3.5 Clean off any burrs, apply flux and tin the outside top 20 mm with solder.
3.6 Take an end feed stop end (e.g. Screwfix Item No. 90441), clean the inside, flux and tin.
3.7 Put the stop end on top of the pipe and re-heat until the solder melts, then push the stop end down.
3.8 A fine skim of mortar over the top.
4. If you have access to a lathe:
4.1 Get some 15 mm brass bar.
4.2 Make up plugs with a 20 mm length turned down to 13.6 mm.
4.3 Tin pipe and plug (inside of pipe, outside of plug) as above, then heat and push into pipe.
4.4 Finish with mortar.

 

[Dazz71]

Ah, poo. I was hoping that there would be an internal way to do it.

Looks like I'm going to have to get the grinding gear out again.

Thanks for the reply

 

[Stuckinarut]

Are you re-routing the pipes I presume? Could you cap off where they tee off from?

 

[Dazz71]

Are you re-routing the pipes I presume? Could you cap off where they tee off from?

No, not rerouting.

At some point I will be taking everything out and replace it all.
I am not able to cap off just yet as we will need a certain amount of the radiators for heating. At least for the next month, and possibly for next winter.

Once the rads are gone I'm going to do nothing with them, just leave what's left of the pipes there in the concrete.

I just want the pipes (in the first part of the reno) to be bunged up or capped off as low as possible so I can self level over them then put a floor down.

I had thought of just dropping a crap load of cement down the pipes, but I am a bit worried about the water pressure from the existing radiators.

 

[Stuckinarut]

What I mean is, there should be a tee or manifold where the pipes in concrete connect to, so could you blank off from that end?

 

[Dazz71]

What I mean is, there should be a tee or manifold where the pipes in concrete connect to, so could you blank off from that end?

No. The only pipes that go from the boiler in to the concrete is one 22mm flow, and one 22mm return. No 15mm's.

What it seems they did was dig footings. Then set up all central heating pipes etc. Then lay the concrete slab over everything. So no access to the pipes at all until they come up from through the slab.

 

[Stuckinarut]

Oh I see, doesn’t appear feasible then.